Triaxial Ultra-Small Strain Measurements Using Laser Interferometry

    Volume 28, Issue 6 (November 2005)

    ISSN: 0149-6115


    Published Online: 31 August 2005

    Page Count: 9

    Heymann, G
    Professor, University of Pretoria, Pretoria,

    Clayton, CRI
    Professor of Infrastructure Engineering, University of Southampton, Southampton,

    Reed, GT
    Professor of Optoelectronics, University of Surrey, Buildford,

    (Received 6 March 2003; accepted 7 April 2005)


    This paper describes a prototype device for ultra-small strain triaxial stiffness measurement, using laser-optic interferometry, and based upon the Fabry-Perot principle. The results of a test on an intact specimen of weak rock are presented, and comparisons made between measurements using this device and a submersible LVDT system. The displacement resolution of the interferometer was 0.0006 μm and the strain resolution 8 × 10−7%. It is shown that the measurement uncertainty of the instrument was low compared with the magnitude of the displacements measured and in addition it was sufficiently accurate to detect the linear stress-strain behavior of a weak rock.

    Paper ID: GTJ10406

    DOI: 10.1520/GTJ10406

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    Title Triaxial Ultra-Small Strain Measurements Using Laser Interferometry
    Symposium , 0000-00-00
    Committee D18